Patents by Inventor Zhifei Fan

Zhifei Fan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10716146
    Abstract: A universal Channel Reservation Signal (CRS) is transmitted by a wireless network node on a frequency channel upon successful Clear Channel Assessment (CCA). The channel reservation signal includes a preamble that has a predetermined pattern, a message having a same short period waveform as the preamble, and a synchronization field (SYNC) disposed between the preamble and the message. The message is encoded to prevent any and all occurrences therein of at least one of the predetermined pattern or a combination of the predetermined pattern and at least part of the SYNC. The universal CRS can be transmitted and successfully received and processed by both NR-SS devices and devices of at least one other wireless communication protocol having a different numerology, such as WiFi. Thus, information can be shared and used to avoid transmitting or to reduce or avoid collisions and interference between devices of different RATs.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: July 14, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhifei Fan, Xiaoxia Zhang
  • Publication number: 20200221446
    Abstract: A base station may access a channel following a successful channel access procedure. The base station may transmit an indication of a resource allocation to a user equipment (UE). The resource allocation may include an allocation of resources for subsequent communications between the base station and the UE, for example, defining a set of transmission time intervals (TTIs) during which the UE may transmit repetitions of uplink control information. The UE may also perform a channel access procedure to access the channel. The UE may transmit repetitions of the uplink control information using the set of TTIs according to the resource configuration. In some cases, the UE may stop transmitting uplink control information repetitions after a maximum number repetitions also according to the resource configuration. The base station may then receive and combine the uplink control information.
    Type: Application
    Filed: December 18, 2019
    Publication date: July 9, 2020
    Inventors: Wooseok Nam, Zhifei Fan, Tao Luo, Yan Zhou, Xiaoxia Zhang, Jing Sun
  • Patent number: 10707987
    Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may be a UE. The UE determines CSI. The UE determines whether to send the CSI based on at least one of a timer or a threshold. The UE sends the CSI upon determining to send the CSI. The UE may send the CSI in a MAC header upon determining to send the CSI. When the UE determines whether to send the CSI based on the threshold, the UE may determine whether to send the CSI based on a difference between the CSI and reference CSI. The UE may determine the reference CSI based on at least one of previously reported CSI, fixed CSI, or an MCS of a received data transmission from a base station. The UE may send CSI to the base station in an initial connection setup with the base station.
    Type: Grant
    Filed: January 18, 2017
    Date of Patent: July 7, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Hao Xu, Tingfang Ji, Peter Gaal, Wanshi Chen, Zhifei Fan, Yongbin Wei
  • Publication number: 20200214040
    Abstract: Methods, systems, and devices for wireless communication are described. A first wireless device may receive a clear to send signal based precoded based at least in part on a receive filter at a second wireless device. The first wireless device may calculate a transmit precoder based at least in part on the clear to send signal. For example, the first wireless device may calculate a whitening filter and a second filter based at least in part on the clear to send signal. The first wireless device may transmit a request to send signal precoded by the transmit precoder to initiate communications with a third wireless device without significantly interfering with ongoing communications at the second wireless device.
    Type: Application
    Filed: March 6, 2020
    Publication date: July 2, 2020
    Inventors: Zhifei Fan, Taesang Yoo, Xiaoxia Zhang, Seyed Ali Akbar Fakoorian
  • Publication number: 20200205192
    Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) and a base station may communicate in an unlicensed spectrum (e.g., a shared radio frequency spectrum band). As such, the UE may determine a codebook size for transmitting hybrid access request (HARQ) acknowledgement (ACK) feedback with respect to the unlicensed spectrum. Accordingly, the UE may base the HARQ ACK codebook size on a number of HARQ processes with which the UE has been configured. Additionally or alternatively, the UE may base the HARQ ACK codebook size on a number and/or duration of downlink channel monitoring occasions indicated by the base station. In some cases, the UE may base the HARQ ACK codebook size on a combination of the techniques described herein.
    Type: Application
    Filed: March 2, 2020
    Publication date: June 25, 2020
    Inventors: Xiaoxia Zhang, Zhifei Fan, Kapil Bhattad, Jing Sun, Tamer Kadous, Srinivas Yerramalli
  • Publication number: 20200196317
    Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may transmit a precoded reference signal to prevent interference with an incoming signal from a base station. The UE may determine a precoder for the reference signal based at least in part on a whitening matrix. In some examples, the UE may determine the precoder based at least in part on the whitening matrix and an effective channel between the base station and the UE. The precoded reference signal may be used by devices in other wireless communications systems to avoid interfering with a signal being received by the UE. In some examples, the UE may alternatively or additionally transmit an indication of the number of additional layers of the link between the UE and the base station that may be nulled out for a second link.
    Type: Application
    Filed: February 20, 2020
    Publication date: June 18, 2020
    Inventors: Seyed Ali Akbar Fakoorian, Xiaoxia Zhang, Taesang Yoo, Zhifei Fan
  • Patent number: 10616839
    Abstract: Over-the-air phase synchronization for reciprocity-based coordinated multipoint (CoMP) joint transmission is discussed. The base stations of the CoMP group and served user equipment (UEs) each transmit phase synchronization reference signals (PSRS). The receiving nodes will compute co-phasing values representing the phase difference between pairs of the PSRS. For example, the difference between two downlink PSRS computed at the UE for a downlink co-phasing value, and the difference between a single PSRS received at two base stations computed at the base station for an uplink co-phasing value. The base stations of the CoMP group may determine a phase compensation by computing the differences between the uplink and downlink co-phasing values and use that phase compensation to adjust communications by the base stations in the CoMP group. In other aspects, the computed co-phasing values may be used to modulate each nodes transmission of its respective PSRS.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: April 7, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhifei Fan, Taesang Yoo, Xiaoxia Zhang, Seyed Ali Akbar Fakoorian
  • Patent number: 10609714
    Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may transmit a precoded reference signal to prevent interference with an incoming signal from a base station. The UE may determine a precoder for the reference signal based at least in part on a whitening matrix. In some examples, the UE may determine the precoder based at least in part on the whitening matrix and an effective channel between the base station and the UE. The precoded reference signal may be used by devices in other wireless communications systems to avoid interfering with a signal being received by the UE. In some examples, the UE may alternatively or additionally transmit an indication of the number of additional layers of the link between the UE and the base station that may be nulled out for a second link.
    Type: Grant
    Filed: July 10, 2018
    Date of Patent: March 31, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Seyed Ali Akbar Fakoorian, Xiaoxia Zhang, Taesang Yoo, Zhifei Fan
  • Patent number: 10602453
    Abstract: Methods, systems, and devices for wireless communications are described. A base station may determine a set of power control parameters for a user equipment (UE) to use in different power control loops. The base station may indicate a power control process for the UE to perform in downlink control information. The UE may identify a subset of the power control parameters to use in a power control loop for the indicated process. In some examples, the power control parameters may be for different sounding reference signal processes, such as uplink channel sounding, downlink channel sounding with channel reciprocity, or cross-link interference. In some other examples, the power control parameters may be for power control loops of different uplink channel configuration. The base station may convey the set of power control parameters to the UE by radio resource control signaling.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: March 24, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Seyed Ali Akbar Fakoorian, Xiaoxia Zhang, Taesang Yoo, Zhifei Fan
  • Patent number: 10595293
    Abstract: Methods, systems, and devices for wireless communication are described. A base station may establish a transmission gap between downlink (DL) and uplink (UL) transmissions on a shared radio frequency (RF) spectrum band using time division duplex (TDD). The gap length may be based at least in part on a maximum allowed length of a filler signal corresponding to a coverage area of the base station. To reserve the shared band, a user equipment (UE) may communicate the filler signal for a length of time that is based at least in part on the maximum allowed length and a geographic distance between the UE and the base station. UEs farther from the base station transmit the filler signal of shorter lengths before sending an UL transmission, so that the UL transmissions from different UEs arrive at the same time at the base station regardless of the geographic distance between the UEs.
    Type: Grant
    Filed: December 11, 2018
    Date of Patent: March 17, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Taesang Yoo, Juan Montojo, Jing Sun, Zhifei Fan
  • Patent number: 10588159
    Abstract: Consideration of contention windows with spatial listen before talk (LBT) operations is discussed. In multiple input, multiple output (MIMO) transmission operations over a shared transmission medium, use of spatial LBT transmissions may be implemented with fairness options and parameters influenced by a condition of the MIMO transmitter, such conditions as the level of MIMO capability or the enablement of polite spatial LBT nulling transmissions. When a MIMO transmitter identifies data for transmission, it may determine a configuration of the medium access contention operation, synchronous or asynchronous content, based on the condition of the MIMO transmitter. The MIMO transmitter may then transmit the data either using spatial LBT transmission or not according to the configuration of the medium access contention operation.
    Type: Grant
    Filed: May 10, 2018
    Date of Patent: March 10, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoxia Zhang, Taesang Yoo, Seyed Ali Akbar Fakoorian, Zhifei Fan
  • Patent number: 10588151
    Abstract: Methods, systems, and devices for wireless communication are described. A first wireless device may receive a clear to send signal based precoded based at least in part on a receive filter at a second wireless device. The first wireless device may calculate a transmit precoder based at least in part on the clear to send signal. For example, the first wireless device may calculate a whitening filter and a second filter based at least in part on the clear to send signal. The first wireless device may transmit a request to send signal precoded by the transmit precoder to initiate communications with a third wireless device without significantly interfering with ongoing communications at the second wireless device.
    Type: Grant
    Filed: May 2, 2018
    Date of Patent: March 10, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhifei Fan, Taesang Yoo, Xiaoxia Zhang, Seyed Ali Akbar Fakoorian
  • Publication number: 20200068625
    Abstract: Physical Random Access Channel (PRACH) interlacing is disclosed. In a particular implementation, a method of performing wireless communications adjusting, by a user equipment (UE) based on a cyclic prefix (CP) length of a received Physical Random Access Channel (PRACH) configuration, CP length of one or more uplink channels to match the CP length of the PRACH configuration. The method additionally includes transmitting, by the UE, the one or more uplink channels interlaced with a PRACH channel that corresponds to the PRACH configuration. The PRACH channel and the one or more uplink channels are aligned.
    Type: Application
    Filed: July 25, 2019
    Publication date: February 27, 2020
    Inventors: Xiaoxia Zhang, Jing Sun, Kapil Bhattad, Zhifei Fan
  • Publication number: 20200007291
    Abstract: Aspects of the present disclosure describe receiving downlink signaling from an access point, determining, based at least in part on the downlink signaling, one or more precoders for uplink signaling, transmitting, to the access point and based at least in part on the one or more precoders, uplink signaling, and receiving, from the access point and based on transmitting the uplink signaling, a precoder indication to use the one or more precoders or one or more other precoders in transmitting uplink communications to the access point.
    Type: Application
    Filed: September 11, 2019
    Publication date: January 2, 2020
    Inventors: Xiaoxia Zhang, Taesang Yoo, Juan Montojo, Zhifei Fan, Renqiu Wang, Yi Huang
  • Publication number: 20190349826
    Abstract: Methods, systems, and devices for wireless communications are described that provide for mobility between base stations for a UE that may be in a coverage extension (CE) mode or a non-CE mode. A serving base station may provide a UE with an indication of one or more neighboring base stations within a same public mobile land network (PLMN). The UE may then prioritize base stations in the same PLMN ahead of other neighboring base stations within a same frequency priority in a reselection procedure. In some cases, a base station may allocate PLMN-specific CE mode random access resources and transmit CE mode broadcast transmissions upon request from a UE within the PLMN. In some cases, a UE operating in CE mode may use contention-based random access resources for random access requests rather than dedicated random access resources.
    Type: Application
    Filed: May 8, 2019
    Publication date: November 14, 2019
    Inventors: Zhifei Fan, Xiaoxia Zhang, Jing Sun, Andrei Dragos Radulescu
  • Patent number: 10477592
    Abstract: Systems and methods herein determine whether an uplink RACH request and/or an uplink autonomous message will be sent using Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM), Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM), or another waveform. The determinations may be based on carrier frequencies, path loss measurements, preconfigurations, and/or more. Further, the systems and methods may send the uplink using time and/or frequency resources that correspond to the DFT-S-OFMD waveform, CP-OFDM waveform, or other waveform. Other aspects, embodiments, and features are also claimed and described.
    Type: Grant
    Filed: November 15, 2017
    Date of Patent: November 12, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoxia Zhang, Tao Luo, Taesang Yoo, Juan Montojo, Zhifei Fan
  • Patent number: 10470242
    Abstract: Phase compensation in a new radio (NR) shared spectrum (NR-SS) coordinated multipoint (CoMP) environment is discussed. A base station may synchronize the phase between one or more additional base stations in a coordinated multipoint (CoMP) group serving one or more user equipments (UEs). This first synchronizing is performed prior to a current transmission opportunity between the CoMP group and the UEs. During transmission, a UE will sent a phase compensation reference signal (PCRS) to help with adjusting a phase drift that exceeds a predetermined threshold. The PCRS may be triggered by a signal from the base station or may be sent routinely by the UE. The UEs will transmit PCRS after each subframe, which the base stations use to adjust the phase.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: November 5, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoxia Zhang, Juan Montojo, Taesang Yoo, Zhifei Fan
  • Publication number: 20190334603
    Abstract: The present disclosure relates to transmitting and receiving improved quality reports using different transmission states. A base station may transmit to a user equipment (UE) a channel comprising multiple beams, wherein the beams include different Transmission Configuration Indicator (TCI) states. The UE can then perform beam quality measurements for the multiple beams. The beam quality measurements can include different channel quality indicator (CQI) measurements and can be performed using the same or different spatial filters. The UE can then determine a combined beam quality report for the different beams and transmit the report to the base station. The beam quality report can also comprise a comparison of, the difference between, or the average of, the different CQI measurements. The UE can also receive a configuration of filtering coefficients from the base station, wherein the beam quality report comprises filtered CQI information.
    Type: Application
    Filed: March 8, 2019
    Publication date: October 31, 2019
    Inventors: Kiran VENUGOPAL, Makesh Pravin JOHN WILSON, Tianyang BAI, Tao LUO, Xiaoxia ZHANG, Zhifei FAN
  • Publication number: 20190335441
    Abstract: An apparatus may determine a beam configuration for a data transmission that includes at least one code block in a first resource block. In certain aspects, the at least one code block may include a first set of bits and a second set of bits. In certain aspects, the beam configuration may include a first beam in a first beam direction that may be used to communicate the first set of bits of the at least one code block in a first set of symbols of the first resource block and a second beam in a second beam direction that is used to communicate the second set of bits of the at least one code block in the second set of symbols of the first resource block. The apparatus may transmit signaling that indicates the beam configuration for the data transmission in the first resource block to a UE.
    Type: Application
    Filed: February 8, 2019
    Publication date: October 31, 2019
    Inventors: Tianyang BAI, Makesh Pravin JOHN WILSON, Tao LUO, Kiran VENUGOPAL, Xiaoxia ZHANG, Zhifei FAN
  • Publication number: 20190335491
    Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive control information indicating a resource allocation pattern for a downlink transmission that is configured for transmission using a plurality of beams and a plurality of mini-slots, where a duration of a mini-slot is less than a duration of a slot. The UE may identify a start time of a first mini-slot of the plurality of mini-slots and a length of the first mini-slot based on the resource allocation pattern, and receive the downlink transmission based on the start time of the first mini-slot and the length of the first mini-slot.
    Type: Application
    Filed: April 23, 2019
    Publication date: October 31, 2019
    Inventors: Kiran Venugopal, Makesh Pravin John Wilson, Tianyang Bai, Tao Luo, Xiaoxia Zhang, Zhifei Fan